126 RAMBLES AND REVERIES. 



processes we need higher powers and more elaborate 

 arrangements. 



The respiration of rotifers is said to be carried 

 on by means of what is termed a " water- vascular 

 system," consisting of two tubes filled with a watery 

 fluid, from which many shorter tubes proceed into 

 the internal parts of the body. The two longer 

 tubes run into a "contractile bladder," which pulsates 

 like a heart, and so keeps up the circulation. 



One curious fact about rotifers must not be 

 omitted, and that is, the sexes are distinct, the 

 females being much more highly organised than 

 the males. The males are more free than the 

 females, but the latter can boast of a superior 

 development, and so probably both are content. 



While we are watching the rotifer, it suddenly 

 loosens its hold of the twig to which it was anchored, 

 and swims away, or perhaps tucks in its wheels 

 and crawls in and out amongst the tangled weeds. 

 We can now see that the tail or foot is forked at 

 the end, and slides in and out like a telescope. 



There are many varieties of rotifers, but I must 

 not overload my pages with technical words, which 

 would require for their explanation more space than 

 I can now spare. Those who wish to pursue the 

 fascinating subject into details must have recourse 

 to Hudson and Gosse's interesting book, or to the 

 ponderous volume of Pritchard. 



I cannot, however, turn away from this group 

 of animals without saying a word about the tube- 

 building rotifers. Perhaps we shall be fortunate 

 enough to find one of these, say the Melicerta. 



